External quality assurance for cervical cytology in developing countries. Experience in Peru and Nicaragua

Environmental Performance of Xylene, Hydrochloric Acid and Ammonia Solution During Pap Stain for Diagnosing Cervical Cancer

BACKGROUND

Little importance has been placed on sustainability of the Papanicolaou (Pap) stain, the gold standard for the diagnosis of cervical cancer, for global environmental health. The standard Pap stain uses environmentally toxic and carcinogenic reactants such as xylene, hydrochloric acid and ammonia solution.

OBJECTIVES

To eradicate the use of environmentally toxic and carcinogenic reactants through the validation of the Ecologic Papanicolaou (Eco-Pap) test.

METHODS

Reagent handling strategies were divided in three phases: used Harris' progressive hematoxilin, polychromatic solution and direct mounting that were analyzed by PEED-Cytology, Staining Quality Index (ICT) and the Bethesda system 2014.

RESULTS

A total of 52,319 Pap smears stained with Eco-Pap were admitted (ICT=0.91). Validation of the Eco-Pap versus conventional staining was optimal (Kappa =0.89) and the sensitivity and specificity of the method were 57% and 98%, respectively. Eco-Pap reduced the environmental contamination produced by xylene (66 liters), hydrochloric acid and ammonia (5.5 liters each) over nine months, and all diagnoses coincided with the cytological details.

CONCLUSIONS

The Eco-Pap is an innovative method that transforms Pap testing into a sustainable and supportable technology.

Improving diagnostic capability for HPV disease internationally within the NIH-NIAID Division of AIDS Clinical Trial Networks

OBJECTIVES

To evaluate an external quality assurance (EQA) program for the laboratory diagnosis of human papillomavirus (HPV) disease that was established to improve international research capability within the Division of AIDS at the National Institute of Allergy and Infectious Disease-supported Adult AIDS Clinical Trials Group network.

METHODS

A three-component EQA scheme was devised comprising assessments of diagnostic accuracy of cytotechnologists and pathologists using available EQA panels, review of quality and accuracy of clinical slides from local sites by an outside expert, and HPV DNA detection using a commercially available HPV test kit.

RESULTS

Seven laboratories and 17 pathologists in Africa, India, and South America participated. EQA scores were suboptimal for EQA proficiency testing panels in three of seven laboratories. There was good agreement between the local laboratory and the central reader 70% of the time (90% confidence interval, 42%-98%). Performance on the College of American Pathologists' HPV DNA testing panel was successful in all laboratories tested.

CONCLUSIONS

The prequalifying EQA round identified correctable issues that will improve the laboratory diagnosis of HPV-related cervical disease at the participating international study sites and will provide a mechanism for ongoing education and continuous quality improvement.

External quality control of cervical cytopathology: interlaboratory variability

OBJECTIVE

To compare the variability of screening tests held at laboratories with the Unit for External Quality Control (UEQC), checking the frequency of cases that were discordant, false-positive, false-negative, unsatisfactory or that had a delay in clinical management and diagnostic agreement.

MATERIALS AND METHODS

The study analyzed 10,053 screening tests from January 2007 to December 2008, including all positive cases, all those that fall under unsatisfactory and at least 10% of negative screening tests. The magnitude of the agreement was analyzed using the kappa coefficient.

RESULTS

Out of the 10,053 cases analyzed, 7.59% were considered disagreeing, and it was estimated that 1.1% were false-negative. There was a delay in the clinical procedure regarding 2.44% cases. There were 2.82% of cases identified as false-positive and 1.24% as unsatisfactory. The diagnostic agreement was excellent (kappa = 0.81). The agreement of most laboratories concerning screening tests was classified as very good. The agreement of the sample adequacy was reasonable (kappa = 0.30) and the agreement regarding the representation of epithelia was considered excellent.

CONCLUSION

Most laboratories showed very good agreement; however, it is worthy of note that to establish the standardization of diagnostic criteria, and enhance the accuracy of screening and improve the quality of cytopathology test results, it is necessary to perform external quality control.

Informatics applied to cytology

Automation and emerging information technologies are being adopted by cytology laboratories to augment Pap test screening and improve diagnostic accuracy. As a result, informatics, the application of computers and information systems to information management, has become essential for the successful operation of the cytopathology laboratory. This review describes how laboratory information management systems can be used to achieve an automated and seamless workflow process. The utilization of software, electronic databases and spreadsheets to perform necessary quality control measures are discussed, as well as a Lean production system and Six Sigma approach, to reduce errors in the cytopathology laboratory.

The development of a quality assurance programme for HPV testing within the UK NHS cervical screening LBC/HPV studies

BACKGROUND

Cervical screening by cytology is effective but lacks sensitivity. The addition of human papillomavirus (HPV) testing can improve the effectiveness of screening for early identification of cervical disease. As HPV testing represents a new technology, a quality assurance (QA) programme is necessary to confirm the accuracy of results.

OBJECTIVE

Our main objective was to design a QA programme for use in the English NHS liquid-based cytology (LBC) and HPV Cervical Screening Pilot Study. Our second objective was to use the knowledge gained to design a QA scheme for future general use within cervical screening and HPV testing programmes.

STUDY DESIGN

Four elements were included in the programme: provision of clinical samples of known HPV status for internal quality control (IQC), distribution of panels of unknown samples for external quality assessment (EQA), resubmission of aliquots of samples to the reference laboratory for repeat testing and resubmission to reference laboratory to check for transport problems. Three sites took part in the QA programme using PreservCyt medium and ThinPrep for LBC preparation. The assay used at test sites was HPV hybrid capture (hc2) while the quality assurance laboratory used a combination of hc2, in-house HPV polymerase chain reaction (PCR) tests and HPV linear array (LA).

RESULTS

Four negative, three low positive and 11 positive pools were used in 22 distributions of IQC samples. Seven distributions each of five 'unknown' EQA samples were sent out. Over 400 samples underwent repeat testing. Discrepant samples were further assessed to provide an explanation. Inter- and intra-laboratory consistency was high as measured by Kappa statistics and 96% agreement for EQA samples was obtained.

CONCLUSIONS

The validity of the QA programme was established and reproducibility in different lab settings was reassuring. These results support the use of hc2 as a potential screening test in diagnostic laboratories. The need for robust quality assurance of HPV testing in cervical screening programmes was confirmed and lessons learnt from this pilot study will be incorporated in future schemes.